Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer. Radiotherapy is an effective treatment for NPC patients with early disease; however, therapeutic strategies remain less successful for patients presenting with metastatic disease or refractory cancer relapse. Bcl3 is an established oncogene in hematologic malignancies. Bcl3 can repress the activation of NF-κB signaling cascade by direct binding to p50, p52, RelA, RelB, or cRel. p50/p50/Bcl3 is the major NF-κB complex being constitutively activated in NPC. Constitutive activation of distinct NF-κB complexes via p50/p50/Bcl3 was found in almost all EBV-positive NPC cells C666-1 and primary NPCs, but not in normal cells. Bcl3 inhibitor has been developed as anti-breast cancer reagent, is shown to reduce 80% metastasis, and is in Phase I clinical trial. Small interfering RNA (siRNA) technology has been applied in gene silencing for cancer treatment in recent years. Over 40 siRNA-based therapeutics have reached the clinical trial stage for treatment of a variety of diseases including cancers, infections, cardiovascular diseases, and genetic disorders. Since naked siRNA is highly unstable, siRNA therapy requires vectors for siRNA delivery. Current dendrimers used as siRNA carriers have limited efficacy, certain toxicity and are not biodegradable.